Softwood interfiber pits

Within a growth ring, softwood interfiber pits are larger and more abundant in earlywood. In latewood they are fewer, smaller, and often appear slitlike in very thick-walled fibers (2). This same type of pit in hardwood fibers varies morphologically with the fiber type, changing from an obviously bordered pit in thin-walled cells to only a slitlike aperture in fibers with thick walls. 

Figure 19. Anatomy of softwood interfiber pits. ( Reproduced from Ref.

The interfiber-pit membranes in softwoods are substantially different from the pit membranes in hardwoods. Much of the membrane periphery is quite open, with only the central portion being nonpo-... 

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